bellwork (3/7/14) what is alternating current (ac)? mr. z. will check off the h.w

Bellwork (3/7/14)Bellwork (3/7/14)

What is alternating current (AC)?What is alternating current (AC)?Mr. Z. will check off the H.W.Mr. Z. will check off the H.W.

Today’s AgendaToday’s Agenda

HomeworkHomeworkBellwork Bellwork Background info and notesBackground info and notesElectricity demosElectricity demos

A – RadioB – Game SystemC – Elec. MotorD – Night LightE – Elec. Oven

Bellwork (3/7/14)Bellwork (3/7/14)

What is alternating current (AC)?What is alternating current (AC)?Electric current that repeatedly Electric current that repeatedly reverses direction in a cyclereverses direction in a cycle

Van de Graaff NotesVan de Graaff Notes

3/7/143/7/14

The Van de Graaff GeneratorThe Van de Graaff Generator

Van de Graaff GeneratorVan de Graaff Generator:: is an is an electrostatic generator which electrostatic generator which accumulates very high voltages on a accumulates very high voltages on a hollow metal dome. hollow metal dome. Size of the dome determines the Size of the dome determines the amount of charge it can storeamount of charge it can store150,000 V150,000 V8000 nC 8000 nC

Background InformationBackground Information

For conductors:For conductors:Charge builds up at pointed surfaces Charge builds up at pointed surfaces and spread out on smooth surfaces.and spread out on smooth surfaces.Inside of conductors the electric field is Inside of conductors the electric field is zerozero..

The Van de Graaff GeneratorThe Van de Graaff Generator

An aside note:An aside note:Rubber Belts – cause the dome to be Rubber Belts – cause the dome to be negatively chargednegatively chargedSilk Belts – cause the dome to be Silk Belts – cause the dome to be positively chargedpositively charged

The Van de Graaff Generator

Electricity DemosElectricity Demos

Pre-Question:Pre-Question:What are the three ways to charge an What are the three ways to charge an object?object?FrictionFrictionContactContactInductionInduction

For each demos:For each demos: (10 total) (10 total)

(a) Name of the demo (name)(a) Name of the demo (name)(b) Describe the demo (description)(b) Describe the demo (description)(c) The electric concept of each demo (c) The electric concept of each demo (concept)(concept)

The Van de Graaff Generator

The Van de Graaff Generator